Why people are so greedy? Let's say X make an innovation that necessitate the use an older patent from inventor Y.

Three things: 1) X has not to pay anything to conceptualize his innovation. 2) X can make a nested patent. 3) a user of the innovation of x must pay a royaltie (why is that an issue?) to Y. If X made a nested patent, the user must pay X and Y. Is this right?

BTW who fixe the amount of royalties?

Presumably each chunk of royalty makes it that much harder to sell a successful product. Often these fess are significantly higher than nearly any other component on the device (think Qualcomm for cellphones and Fraunhofer for mp3 decoding)

Nobody's going to buy the $100 item if it provides $15 amount of value, and nobody's going to make it for $15 if $9 of it is going to licensing.

In which case licensing fees should be explicitly capped. E.g. to a percentage of revenue you make off the device.

That'd stop patent trolls and silly patent holdings dead. You don't use it, you can't charge others.

If someone starts using it, you would charge a percentage royalty.

Exactly, there should be a political push for this!

Yes, but I observe on the net what seems to be an aversion to pay all patents even if it only cost a few cents. The price per unit of the concerned patent is never talked about and this irrational aversion is an issue. Websites displaying patent content should display price too. I don't know if patents are generally overpriced but patent owner have an incentive to maximize their benefits which means they probably want to maximize the number of users of the patents by making it cheap.